This invention relates to dry-wall construction, and specifically to the uniform blending of corners with the oppositely continuing planar surfaces of adjoining walls. That is, it is rounded corners that must be dressed by sanding so that the corner curvature fairs smoothly into the oppositely extending flat walls. And, it is the outside corners that are involved here, corners that are usually at 90.degree., and also corners for example at 45.degree.. It is to be understood that the degree of angularity between next adjacent walls can vary as circumstances require.
The walls are vertical, as are the corners at which the dry-wall panels of gypsum board are angularly abutted. Accordingly, these angularly abutted corners must be completed in a uniform and acceptable manner before the paint and/or finish is applied. In practice, convexly radiused corner members are fastened in place to complete such corners, as shown herein, and which are troweled with a filler cement or paste that drys to a solid state subject to be finished as by sanding, which is the subject of this invention.
Heretofore, finish sanding of dry-wall corners has been a cautious if not difficult operation because of the inherent tendency of the sanding tool edge to cut into and permanently mark the dry-wall surface, the dry-wall surface being comprised of a low grade pulp paper. The soft gypsum core and soft paper surface are easily damaged by the abrasive edge of the sanding tool or cutting edge of heavy sandpaper or the like. When such cutting marks occur, the wall corner must be reconstructed or at least re-troweled and sanded again, all of which is time consuming and an added expense. Accordingly, it is an object of this invention to avoid abusive sanding and to eliminate the probability of damaging sanding marks. With the present invention, the oppositely extending sanding planes of the tool are obtusely related with respect to the angle of the corner being sanded thereby. For example, obtuse with respect to a 90.degree. corner, and also with respect to a 45.degree. corner, or any other corner angle as circumstance may require.
Sanding tools of the type under consideration have been provided with extension poles in order to sand out of reach heights. These tools have been swivel mounted to the top end of the poles so as to be free to assume angular positions with repsect to said poles. In other words, the sanding tools have been gimbal mounted at the end of the poles, and which mounting has been found to be detrimental to the tool function of sanding. Firstly, before application to the wall surface the tool will fall into extreme positions incompatible with the wall surfaces. Secondly and of unobvious importance, when the tool is in place over the corner to be sanded, the loose gimbaled mounting of the prior art tools precludes control thereof by the pole. However, with the present invention, it is an object to control the sanding tool by rocking it into the desired position responsive to manual positioning of the pole. Accordingly, the gimbaled mounting of the sanding tool at the end of the pole is frictionally adjustable, a ball and socket joint or right angular pivotal axes as shown herein.
It is an object of this invention to provide an adapter for recieving a corner sanding tool having the angular features referred to, whereby sanding tools of preferred angularity can be mounted for dressing wall corners of certain angles, 90.degree. or 45.degree. or any other angle. In practice, the opposite sides of the sanding tool deviate approximately 15.degree. from the planar surface of the continuing wall plane. This obtuse angularity separates the outer edge of the tool surface from either continuing wall, while the radius of the corner member remains uniform, for example a 3/4 inch radius. In accordance with this invention , the sanding element is backed by a firm padding carried by a rigid body conforming to the aforesaid corner radius and to the angularity of the corner to be rounded, for example, concentric with a 3/4 inch corner radius and opposite sides divergent at 120.degree., for dressing a 90.degree. corner. It is an object of this invention to provide an adapter to receive the aforesaid tool, whether it be a 90.degree. or a 45.degree. or any other angle of sanding tool. It is still another object to provide a replaceable sanding tool that is releasably applied to said adapter gimbaled at the end of a pole that is adapted to control said sanding tool. In practice, the body of the sanding tool is held to the adapter by self threading screw fasteners, or by means of darts.
The foregoing and various other objects and features of this invention will be apparent and fully understood from the following detailed description of the typical preferred forms and applications thereof, throughout which description reference is made to the accompanying drawings.